Analysis of variability in activity-travel patterns based on multi-day GPS-imputed travel diaries

This paper addresses the issue of day-to-day variability in activity-travel behavior. First, multidimensional sequence alignment is applied to measure the degree of dissimilarity in individual daily activity-travel sequences between pairs of travel days. Next, a panel effects regression model is used to estimate the effects of socio-demographics and days of the week on the degree of dissimilarity in dayto-day activity-travel sequences. The data on activity-travel patterns were collected using GPS-enabled smartphones and a prompted recall survey instrument. Results show that days of the week have significant effects on the variability in day-to-day activity-travel behavior; the degree of dissimilarity in activity-travel sequences is strongly influenced by respondent socio-demographic profiles; individuals having more control over and more flexibility in their work schedule also show greater intrapersonal variability. The paper ends with a discussion of the limitations of this study and the implications of the research findings for future research.